Currently, some magnetic recording technology utilizes magnetoresistive ("MR") heads in order to read data stored on a magnetic recording media, such as a disk. Conventional MR heads include a conventional MR element which has a resistivity that depends upon the magnetization of the MR element. Such heads also include electronics which translate the change in resistivity of the MR element into a signal that indicates the state of a bit being read.
Generally, conventional MR elements utilize one of two physical phenomenon to read the state of a bit magnetically stored on the disk. Anisotropic magnetoresistive ("AMR") elements rely on the change in resistivity of a material as the direction of magnetization in the material changes. A giant magnetoresistive ("GMR") element depends upon the scattering at an interface within the GMR element. Typically, this interface is between non-magnetic and magnetic layers in a multilayer structure. GMR is typically significantly greater than AMR.
Irrespective of the physical phenomenon used in the conventional MR element, the magnitude of the signal provided by the conventional MR head in response to the magnetization of a bit depends upon several parameters. The magnitude of the signal is proportional to the sheet resistance of the conventional MR element and to the efficiency of the conventional MR element. The efficiency is the average magnetic flux through the MR element divided by the maximum flux through the MR element. The magnitude of the signal is also proportional to the current driving the conventional MR element.
A trend in magnetic recording technology is to higher density storage. In order to increase the density of data storage, the length and width of each bit are made smaller. As each bit is made smaller, the effect of the bit's magnetic field on the MR element is reduced for a variety of reasons. Consequently, the magnitude of the signal provided by the MR head decreases. As the magnitude of the signal provided by the MR head decreases, the MR head may become incapable of reading the data stored on the disk.
Accordingly, what is needed is a system and method for improving the ability of a magnetoresistive head to adequately read information stored in a magnetic recording media. The present invention addresses such a need.